fix indents
create root node first

root node template makes <resource> tag and calls <xsl:apply-templates>
within.
make generic template to get identifier element
refactor code to find <identifier>

There should only be one DOI, so no need to call loops
move "dim:dim" template start/end

variables can be declared outside of this template.
fix indents
handle finding non-dim data for datacite

template parse_mets finds datacite data that is not stored in DIM.